To provide an oxygen concentrator that can reduce pressure loss when suctioning raw air and that can increase the amount of suctioned raw air by an amount of reduction in pressure loss, and moreover that can reduce noise without significantly changing a basic structure of a compressor. The oxygen concentrator includes: a compressor that has a plurality of suction ports suctioning raw air and that generates compressed air by compressing suctioned raw air; a conduit through which the compressed air is sent; a silencer that has a suction side end introducing the raw air and a discharge side end discharging the raw air, with the silencer being connected with the conduit; and a plurality of connection conduits directly connecting the discharge side end of the silencer and the respective suction ports of the compressor.